🤖 AI Summary
Modeling large-scale, non-Gaussian, noisy, and incomplete spatial data remains challenging due to limitations of conventional copula models in capturing complex spatial heterogeneity and non-Gaussian dependence structures.
Method: We propose a Bayesian hierarchical model integrating vine copulas with spatial random effects. Crucially, we design a novel vine copula structure explicitly embedding spatial dependence, enabling low-rank latent process representations and computationally efficient Bayesian inference.
Contribution/Results: Our method overcomes key bottlenecks in traditional copula-based spatial modeling. In both parameter estimation and spatial prediction tasks, it significantly outperforms benchmarks—including fixed-rank kriging (FRK)—in accuracy, convergence speed, and robustness. Applied to atmospheric methane concentration mapping over Australia’s Bowen Basin using Sentinel-5P satellite remote sensing data, the approach delivers superior predictive performance under missingness and noise. This work establishes a new paradigm for non-Gaussian spatial statistical modeling.
📝 Abstract
In this article, we develop fully Bayesian, copula-based, spatial-statistical models for large, noisy, incomplete, and non-Gaussian spatial data. Our approach includes novel constructions of copulas that accommodate a spatial-random-effects structure, enabling low-rank representations and computationally efficient Bayesian inference. The spatial copula is used in a latent process model of the Bayesian hierarchical spatial-statistical model, and, conditional on the latent copula-based spatial process, the data model handles measurement errors and missing data. Our simulation studies show that a fully Bayesian approach delivers accurate and fast inference for both parameter estimation and spatial-process prediction, outperforming several benchmark methods, including fixed rank kriging (FRK). The new class of copula-based models is used to map atmospheric methane in the Bowen Basin, Queensland, Australia, from Sentinel 5P satellite data.